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By Roy C. Kirkman

It is with great pleasure that I read Mr. Howard M. Wells article in the December 1978 issue of MINING ENGINEERING entitled: "Optimization of Mining Engineering Design in Mineral Valuation." Mr. Wells very adequately presents the case and point that there are a great number of variables which must be analyzed during an economic evaluation of an FUND RESOURCE, such as copper or uranium.

Jan 4, 1979

Correspondent. Must be able, by virtue of, connection, to forward; daily ands weekly, reports, outlining, conditions affecting economics of. industries, particularly the metallurgical, and chemical, industries. New. York, City. R-1982. Sales Lubrication. Engineer. Preferably with experience, as chief marines engineer familiar with internal-combustion; engines and, with, automobile trade. Must be good salesman, of goody appearance and be able to meet people. Middle West. Salary $27.00: to start. R71984.

Jan 12, 1919

C. A. HANSEN (communicated appendix*).-Since the above paper was written, tests have been conducted with a view to securing a sounder basis for discussing the effects of temperature on the behavior of the zinc cell. The following data, while making no pretense to great accuracy, are still reasonably close. Cells were operated with the same feed solutions, but at varying temperatures, the latter being controlled by means of immersed steam coils. Current efficiencies obtained indicate that the corrosion rate

Jan 11, 1918

By Smith Bracewell

First evidence of bauxite in Jamaica resulted from an analysis of a soil sample collected at Bull Savannah in 1938 during a systematic local investigation of the island's soil types. Results of subsequent work indicated the possibility of the occurrence of deposits of commercial grade and dimensions, and in 1942, with a view to emergency development of the deposits as a war measure, the Jamaican Government declared all bauxite in the colony to be Crown property.

Jan 10, 1958

Jan 1, 1930

By Eugene P. Pfleider

Research indicates that the cube diamond is a superior stone for drill bits. It can be oriented to combine a long cutting edge with structural strength and high resistance to wear. Test bits set with preferred orientation give double the bit life at astoundingly low diamond loss in comparison to oriented octahedral diamonds.

Jan 10, 1953

POSITIONS VACANT The National Bureau of Standards needs men to fill metallurgical positions with salaries varying from $1200 to $2000, depending upon the training and experience of the candidate. Experience either in ferrous. or, non-ferrous metallurgy. Duties will be almost entirely of an investigational nature, in connection with problems of military importance. Qualified men are urged to send to the Bureau of Standards at once a statement of training and experience, names of references, acid minimum salary that would be accepted, so that they may he advised of appropriate civil service examination for which to file papers. Until further notice, such papers are received by the Civil Service Commission at any time and ratted promptly.

Jan 10, 1917

By A. M. Radigan, W. G. Prast

Various industrial minerals that are traded internationally receive support from governments, enabling these materials to be more competitive. The role of government in encouraging nonmetallics exports ranges from the ownership of an integrated mining company to partial or selective government ownership, to the sponsorship of exporter organizations. In certain cases, regional governments have a direct stake in the industrial minerals industry. This paper assesses the commercial impact of these involvements.

Jan 1, 1984

By F. N. Pease, C. B. Dudley

Those who have worked a good deal on the chemistry of pig-irons of which the physical properties were known, cannot fail to have been struck by the remarkable want of relation between the physical properties of different samples, and the ultimate chemical composition. It is very well known among foundrymen that irons which will give say 4 inch of chill, and are, therefore, approximately the same in chemical composition, are very far apart, many times, in their physical properties. The foundryman's tests for strength are, of

Jan 1, 1886

By A. E. Wells, H. O. Hofman, R. P. Reynolds

A Discussion of the Paper of H. O. Hofman, R. P. Reynolds and A. E. Wells, read by title at the London Meeting, July, 1906 ; presented at the New York Meeting, April, 1907, and printed in Bi-Monthly Bulletin, No. 13, January, 1907, pp. 37 to 52. GEORGE A. PACKARD, Boston, Mass. (communication to the Secretary*) :-The very interesting results obtained by Prof. Hofman and his assistants came to my attention when I had temporarily assumed charge of the metallurgical department of the Missouri School of Mines, and had found it, pending the completion of a new building, lacking a furnace in which to roast ore preparatory to the customary lead blast-furnace run. An attempt at lime-roasting had been already determined upon, but the use of a charge which would make a slag of definite composition was a new idea. The results following were obtained by Messrs. Aubrey Fellows, J. C. Long, E. R. Wash, and Dr. T. C. Tseung, under my supervision. It is regretted that the data are not more complete; but the work was done simply incidentally to securing the desired ore for the blast-furnace, with no idea of obtaining any results of especial interest. It is submitted because of the metallic lead obtained, no notice of which has been seen elsewhere. The ore was an aggregate of several lots of concentrates, apparently from Missouri ores. The analysis follows, with that of the limestone and sandstone used, as far as made:. Ore, SiO2, 3.04; Fe, 0.77; CaO, 2.53; Pb, 68.74; Zn, 5.77; S, 13.9 per cent.; limestone, SiO2, 1.0 ; CaO, 54.35 per cent.; sandstone, SiO2, 99.8 per cent. The converter was made in the shops from a sheet of No. 14 iron riveted in the shape of a truncated cone, 20 in. in diameter at the top, 15 in. at the bottom and 22 in. high. A grate of No. 8 iron, 17 in. in diameter, with 130 s-in. holes placed at about 1.25-in. centers, was held in place by the shape of the

Jul 1, 1907

By Charles Catlett

The terms " developed " and " undeveloped " are necessarily relative and cover a wide range; but the latter is here applied to cases in which the information at hand falls short of a clear demonstration of values, and conclusions must be reached frorn a study of the geological conditions of the particular deposit, interpreted in the light of similar and closely-related deposits. Such an inquiry might be characterized as an effort to reach reliable conclusions from insufficient data. But the engineer

Jan 1, 1909

Executive SIDNEY .J. JENNINGS, Chairman GEORGE D. BAR HON .I. E. JOHNSON, JR. EDWIN LUDLOW ROBERT M. RAYMOND Membership KARL EILERS, chairman LEWIS W. FRANCIS .1. E. JOHNSON, JR. LOUIS D. HUNTOON ARTHUR. L. WALKER Finance GEORGE D. BARRON. Chairman. CHARLES F. RAND BENJAMIN B. THAYER Library E. GYBBON SPILSBURY1 Chairman ALEX C. HUMIPHREYS3 GEORGE C. STONE .J. H. JANEWAY4 BRADLEY STOUGHTON Papers and Publications BRADLEY STOUGHTON, Chairman

Jan 10, 1918

Jan 1, 1955

By George A. Yurko

The Cominco smelter, located at Trail, British Columbia, Canada, produces 180 000 metric tons of lead bullion annually in conventional blast furnaces. The resulting slag from these furnaces, 210 000 metric tons annually, containing 18 per cent zinc and 2.5 per cent lead, is treated directly in the slag fuming plant for the recovery of these metals and other valuable metals present in smaller quantities. Slag fuming is carried out on a 55 metric ton batch process in completely water-jacketed furnaces where the slag is blown with a mixture of powdered coal and air. The coal-to-air ratio is con- trolled to maintain strongly reducing conditions, thus, fuming the metals from the slag. The metal vapours are subsequently re-oxidized with air above the bath. The mixture of oxides is carried from the furnace by the gases through waste heat boilers and cooling flues to a baghouse where they are collected. The slag fuming plant, under normal conditions, will treat 700 metric tons of slag daily. The throughput in the plant is dependent on the fuming rate of zinc, which is a function of the composition of the slag, and on the economics, which dictate the extent to which zinc is fumed from the slag. Zinc and lead collected daily as fume average 113 metric tons and 17 metric tons, respectively, corresponding to recoveries of 89 per cent zinc and 98 per cent lead from the slag. The waste heat boilers produce 61 metric tons steam per hour, which is distributed to other processing plants.

Jan 1, 1970

By E. T. Turkdogan, P. Grieveson

Experimental results are given for the rate of oxidation of ferrous iron to ferric iron in pure molten iron oxide by carbon dioxide + carbon moloxide mixtures at 1550°C. It is shown that the rate-controlling process is the interdiffusion of iron and oxygen atoms within the melt. The inter-diffusivity of iron and oxygen in the melt is obtained from the results and the value of (5.0 * 1.0) x 10-5sq cm per sec is recommended for the temperature of 1550°C. Similarly, it is also found that the rate of reduction of molten iron oxide is con -trolled by diffusion in the melt; however, apparent interdiffusivity values from these experiments are 10 to 20 pct higher than those obtained in the oxidation experiments, by virtue of convection arising from density difference. The results of the oxidation experintents are used to calculate an estimated self-diffusivity of iron in molten iron oxide of (1.5 * 0.5) x sq cm per sec. BECAUSE of the industrial importance of iron oxides, the study of the kinetics of both the reduction and oxidation of the solid oxides has received a great deal of attention. However, knowledge of the kinetics of similar reactions in the liquid state is very meager. Dancy 1 studied the kinetics of reduction of molten iron oxide by carbon in pig iron and found that the reaction is very fast. It was concluded from the results that the reduction of molten ferrous oxide is a first-order reaction up to 80 pct reduction, while

Jan 1, 1964

By Tran K. Van, Francois E. Heuzé, Richard E. Goodman

Sound design of structures founded in or upon rock requires that the deformability of each rock member involved be characterized. This can be done by means of loading tests (plate bearing, flat jacks, borehole jacks, pressure chambers, etc.) or through convergence measurements (tunnel convergence, roof sag, etc.) in exploratory works. Analysis of data will be qualitative (degree of nonlinearity, creep behavior, scattering of results over a number of sites, etc.) and quantitative (modulus of elasticity or deformation). Some of these tests involve a very bulky apparatus and are expensive to perform. On the other hand, for the purpose of mapping and describing the various rock members which occur within a given site, many feet of diamond drill holes are frequently completed. Even with the optimum equipment and expert drillers, however, quantitative characterization of the rock units on the basis of tests on returned samples is apt to be misleading; the softer and weaker components of the rock tend to be lost and the fabric of the rock block- fracture system in situ is not sampled. Laboratory moduli of elasticity have proved to be consistently higher than in-situ values selected for engineering purposes. This led to the design of instruments which would operate in boreholes, combining the advantages of a reduced size and a deeper investigation, from the surface to several tens of feet. BOREHOLE DEFORMABILITY MEASURING INSTRUMENTS In the last 10 to 15 years, a number of testing devices have been con- structed which can be inserted into a borehole to apply a load and mea-

Jan 1, 1972

By W. A. Knoll

THE sinking of a new shaft at the Newport mine, Ironwood, Mich., was started in May 1931 and completed on Aug. 3, 1932. During this period, 2665 ft. of shaft in granite was completed, at, an average advance of 6 ft. per 24 hr. In November of 1930, experimental work was con-ducted oil 65 ft. of shaft through 22 ft. of overburden where ledge was encountered, and this work convinced the operators that all drilling could be clone with vertical holes with the blasting relief to a 4 ½ -in. hole drilled vertically in the center of the cut. The reason for not adopting the conventional V-cut was to get away from damaging the shaft steel. The blasting in a V-cut naturally tends to throw the broken material upward, but with the cut as adopted the relief was in a horizontal direction to a large extent. The scheme of mucking employed made it necessary to keep the steel shaft sets within 511 ft. of the bottom at all times. This could not be clone without serious damage with a V-cut when blasting in granite. The cut as drilled also broke 10.53 ft. per round of drilling, which was considerably more than the experience with a V-cut in the sane material. The extended cut reduced proportionately the delays for charging, blowing smoke and handling drilling equipment in the shaft. Another advantage was the ease in drilling vertical over inclined holes, and the preservation of the proper spacing of the drill holes at the bottom of the cut.

Jan 1, 1938

By N. A. Ziegler

A CERTAIN amount of interest has been indicated recently in the resistance to oxidation at high temperatures of iron-aluminum alloys (rich in iron). Hautman1 published a paper in which some interesting results are given. According to his paper, only alloys containing at least 8 per cent aluminum indicate a marked improvement in their resistance to oxidation. At about this aluminum content, however, alloys become brittle, which considerably reduces their commercial value. About two years ago the author performed a series of experiments, the results of which are presented here. A series of iron-aluminum-carbon alloys was prepared by melting electrolytic iron, aluminum and high-carbon iron alloy in an induction vacuum furnace.2 The list of these alloys is given in Table 1. Each alloy was forged in the ordinary way to

Jan 1, 1932

THE following statement is contained in an article entitled "Mortgaging the Future." by Walter C. Teagle, president of the Standard Oil Co. of New Jer-sey, appearing in the current issue of the Lamp, the official organ of the Standard Oil Co.: "During the last eight months the domestic daily production. of crude oil has risen 300,000 bbl.. which means that no less a volume than 2,500,000 bbl. now are coming to market each day. . . . Every twenty-four hours 250,000 bbl. more than the consumer required are being added to our surplus oil storage. The temporary advantage of cheap petroleum products and the availability of fuel .oil, for a widespread use as a substitute for coal are not being weighed against the time when scarcity may follow on the heels of plenty and the public of tomor-row may have to pay for today's excesses. The over-production of crude and its consequences constitute a problem of national import which far outweighs the temporary advantages either to a part of the industry or to sections of the public.

Jan 8, 1927

By J. A. Kitchener, J. P. Anfruns

Measurements have been made of the rate of capture of single particles of strongly hydrophobic, surface-methylated, quartz, of sizes ranging from 12 to 40 µm diam., by single rising bubbles of diam. 0.5 to 1.1mm. The results agree closely with the theoretically calculated hydrodynamic collision rates, indicating that, in this system, every collision results in capture and retention of a particle.

Jan 1, 1976